x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards
commit472a474c6630efd195d3738339fd1bdc8aa3b1aa
authorSuresh Siddha <suresh.b.siddha@intel.com>
Thu, 1 Apr 2010 01:04:47 +0000 (31 18:04 -0700)
committerIngo Molnar <mingo@elte.hu>
Fri, 2 Apr 2010 18:48:47 +0000 (2 20:48 +0200)
tree010b5b8191eba821b4940b4ab9fbd48ed468afa0
parent51591e31dcb3716f03f962e26ec36a029aa46340
x86: Fix double enable_IR_x2apic() call on SMP kernel on !SMP boards

Jan Grossmann reported kernel boot panic while booting SMP
kernel on his system with a single core cpu. SMP kernels call
enable_IR_x2apic() from native_smp_prepare_cpus() and on
platforms where the kernel doesn't find SMP configuration we
ended up again calling enable_IR_x2apic() from the
APIC_init_uniprocessor() call in the smp_sanity_check(). Thus
leading to kernel panic.

Don't call enable_IR_x2apic() and default_setup_apic_routing()
from APIC_init_uniprocessor() in CONFIG_SMP case.

NOTE: this kind of non-idempotent and assymetric initialization
sequence is rather fragile and unclean, we'll clean that up
in v2.6.35. This is the minimal fix for v2.6.34.

Reported-by: Jan.Grossmann@kielnet.net
Signed-off-by: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: <jbarnes@virtuousgeek.org>
Cc: <david.woodhouse@intel.com>
Cc: <weidong.han@intel.com>
Cc: <youquan.song@intel.com>
Cc: <Jan.Grossmann@kielnet.net>
Cc: <stable@kernel.org> # [v2.6.32.x, v2.6.33.x]
LKML-Reference: <1270083887.7835.78.camel@sbs-t61.sc.intel.com>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
arch/x86/kernel/apic/apic.c